AnimationSet with setStartOffset not working

Question

I'm trying to run few animations (one after another) on a view using AnimationSet

Scale from 1 --> 0 and than from 0 --> 1

AnimationSet animationSet = new AnimationSet(true);
animationSet.setInterpolator(new AccelerateDecelerateInterpolator());

ScaleAnimation animation1 = new ScaleAnimation(1f, 0f, 1f, 0f, Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f);
animation1.setDuration(500);

ScaleAnimation animation2 = new ScaleAnimation(0f, 1f, 0f, 1f, Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f);
animation2.setDuration(500);
animation2.setStartOffset(500);

animationSet.addAnimation(animation1);
animationSet.addAnimation(animation2);

mFloatingActionButton.startAnimation(animationSet);

The view just disappear and after a sec appear again. No animation.

If I remove the setStartOffset(...) I can see animation, but not the one I want.

What am I missing here?

Answer 1

Chaining animations using start offset rarely behaves as expected. There are several ways to achieve the effect you want:

1) Using ScaleAnimations, you chain the animations using listeners (start the second animation on the onAnimationEnd callback).

2) Using animatorSets (as opposed to animationSets) with playSequentially.

Simplified code for option 1:

final View theView = findViewById(R.id.the_view);
final ScaleAnimation scaleAnimation1 = new ScaleAnimation(1,0,1,0);
final ScaleAnimation scaleAnimation2 = new ScaleAnimation(0,1,0,1);
scaleAnimation1.setAnimationListener(new Animation.AnimationListener()
{
    @Override
    public void onAnimationStart(Animation animation)
    {
    }
     @Override
    public void onAnimationEnd(Animation animation)
    {
        theView.startAnimation(scaleAnimation2);
    }
     @Override
    public void onAnimationRepeat(Animation animation)
    {
    }
});

Simplified code for option 2:

final View theView = findViewById(R.id.the_view);

ObjectAnimator animScaleXSmaller = ObjectAnimator.ofFloat(theView, "scaleX", 0f);
ObjectAnimator animScaleYSmaller = ObjectAnimator.ofFloat(theView, "scaleY", 0f);
AnimatorSet animScaleXYSmaller = new AnimatorSet();
animScaleXYSmaller.setDuration(500);
animScaleXYSmaller.playTogether(animScaleXSmaller, animScaleYSmaller);

ObjectAnimator animScaleXBigger = ObjectAnimator.ofFloat(theView, "scaleX", 1f);
ObjectAnimator animScaleYBigger = ObjectAnimator.ofFloat(theView, "scaleY", 1f);
AnimatorSet animScaleXYBigger = new AnimatorSet();
animScaleXYBigger.setDuration(500);
animScaleXYBigger.playTogether(animScaleXBigger, animScaleYBigger);

AnimatorSet animScaleBounce = new AnimatorSet();
animScaleBounce.playSequentially(animScaleXYSmaller, animScaleXYBigger);
animScaleBounce.setInterpolator(new AccelerateDecelerateInterpolator());
animScaleBounce.start();